The present invention relates to a carrier for confidential or non-confidential data which is both easy to manipulate and easy to transport.
There are a number of known carriers for confidential data. Such carriers may take the form of cards having magnetically or optically readable information encoded thereon. Examples are disclosed in U.S. Pat. Nos. 3,894,756 and 3,919,447. Alternatively, the cards may include electrical circuit elements in the form of integrated circuits. Examples of this general type of data carrier are disclosed in U.S. Pat. Nos. 3,702,464; 3,868,057; 3,876,865; 4,001,550; 4,004,133; and 4,007,355.
Although the last-mentioned type of data carrier is sophisticated, it has the major drawback that it uses specific electronic circuits of set structure which perform a single function determined by the use for which the carrier is intended.
Access to the data is generally obtained by means of a key or code stored in the data carrier and known only to the owner of the carrier. Safeguards are thus provided in the carrier itself which bar access to the data carrier when an attempt is made to gain access using an incorrect key. However, the incorporation of these safeguards in carriers for confidential data known hitherto generally means that dialogues of differnet types take place between the data carrier and the operating apparatus connected to it depending on whether the key used is of the right or wrong type, so that it is perfectly possible for a clever defrauder to tap the data lines connecting the carrier to the operating apparatus and discover the keys which give access to the said data carrier.
Accordingly, it is a first object of the invention to provide a data carrier which has an easily programmable electronic structure and which is able to perform a multitude of functions without it being necessary to endow it with special electronic structures.
It is a second object of the invention to provide a data carrier or card, which may or may not be made specific to an individual, and which may contain both information of a general nature and information of a confidential nature and which includes processing elements for the internal management of the data contained in the data carrier and for the external management of exchanges of data with the operating apparatus connected to the said carrier, the external transaction of exchanges with the operating apparatus apparently remaining the same in the event of anomalies or illicit use whether the key is correct or incorrect.
To be more exact, the data carrier according to the invention is a portable article of small size associated with an electronic arrangement comprising a microprocessor having an electrically programmable read-only memory, the memory characterized in that it has three zones:
(1) a first or secret zone in which only internal reading and writing by the circuits of the data carrier is permitted;
(2) a second or working zone in which any reading and writing operations are permitted; and
(3) a third or read zone where only read operations ordered by electronic devices internal or external to the data carrier are permitted.
The memory is further characterized in that it includes, in the secret zone, an ERROR zone and an ACCESS zone in which information indicating attempted access or access to strictly confidential data requiring the use of a key is stored. The microprogram stores one bit in one or the other of these two zones each time access to the data carrier is requested.
With the arrangement of the invention, it is thus possible to perform read and write functions in predetermined zones of the memory provided that a secret code or key which will be recognized by the arrangement itself is fed into the data carrier.
The operations to be performed are monitored and handled internally and continuously by means of a microprogram which is recorded in the memory of the microprocessor and which is specific to each application. The internal handling thus deprives a would-be defrauder of any opportunity to learn the nature of the information required to use the data carrier.
More particularly, the facilities provided by the complete portable assembly of the invention may be used for:
(1) storing and processing changing financial data;
(2) controlling access to secret or restricted information; and/or
(3) making up a portable confidential or non-confidential file with the opportunity for internal sorting of various kinds of processing.